Four members of the current 25-man roster weren't with the organization a month ago. In Brennan Boesch, Vernon Wells, Lyle Overbay and Ben Francisco, New York overhauled nearly 20 percent of its team in a matter of weeks.

It remains to be seen what type of product the Yankees will provide in 2013, but their collective age, injury situation, easy-to-see impending issues and insistence on moving under the luxury tax will make this season a trying one for General Manager Brian Cashman.

Improving the roster over the course of the season won't be impossible but rather a significant challenge.

As always, the first route should and will be to explore the waiver wire. When that well becomes dry, New York may have to look into the trade market to compete in the balanced American League.

For years, New York had issues commencing mid-season trades because of a barren farm system.

That's not an issue anymore, especially in the lower levels of the farm, but money is. When considering in-season Yankees trade targets, think rentals. If a contract runs past this season, odds are New York wants little to do with it.

Of course, there are exceptions. If a young, cost-controlled star can be acquired, plans could be altered. If a trade partner would pick up most of the tab on a contract—much like Los Angeles did in the Vernon Wells deal—an agreement could be reached.

The three areas of the roster that could need an upgrade between now and August: starting pitching, corner outfield and corner infield.

Starting Pitching

Yes, the strength of the roster can become a issue moving forward. While the organization has enough depth in David Phelps, Ivan Nova, and come mid-season, Michael Pineda, there remains the possibility of injuries and decline to their top arms.

Feldman is an underrated arm that has posted sub-four FIP and xFIP marks in the AL over the last two seasons with the Texas Rangers. His one-year, $6 million deal with Chicago sounded like mid-season trade bait the minute it was announced.

Corner Outfielder

Even if Curtis Granderson recovers from a fractured forearm and returns to form, defense can still be an issue in the Yankees outfield.

While Ichrio Suzuki provided a spark after coming over from Seattle last year, his OBP issues could make him more suited for a fourth outfielder role.

Before arriving in a late July trade last season, Suzuki had a .288 OBP. While his .340 mark with New York represented a major upswing, it was greatly enhanced by a 16-game stretch to end the season where Suzuki hit .394/.405/.563. Prior to that, his OBP was .295 for New York.

Brett Gardner has long been a Brian Cashman favorite, but has missed significant time due to injuries in two of his four seasons in New York.

The trio of Boesch, Wells and Francisco are question marks. In some ways, so are the duo of Suzuki and Gardner.

Trade candidates: Alfonso Soriano, Cubs; Carlos Gonzalez; Rockies

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Gonzalez would be a major cost for Brian Cashman.

Both come with salary concerns—Soriano is owned $36 million through 2014, Gonzalez is owed $71 million through 2017—but could be offset in different ways.

Soriano could represent a better version of the Vernon Wells acquisition. Coming off a 32-homer season in Chicago, the former Yankee would be an instant offensive upgrade. Considering that New York took on money to take a chance on Wells, a trade for Soriano would have to come cheap.

Gonzalez isn't an impending free agent, nor would Colorado pay anything to see him leave. On the other hand, moving him would expedite a Rockies rebuilding effort that could be necessary sooner than later.

While getting under the $189 million luxury tax would be difficult if New York added future payroll this summer, Gonzalez could represent a market inefficiency and allow Brian Cashman a chance to add when his competitors least expect it.

Granderson, an impending free agent, is older and likely to be more expensive than Gonzalez will be from 2014-17.

New York could acquire Gonzalez and account for his future salary by letting Granderson walk in the offseason.

Unfortunately for New York, there's no guarantee of health or production from any of the three former stars.

The good news is Youkilis provides versatility. His ability to switch between 1B and 3B could allow New York to add the best corner infielder possible, regardless of which side of the infield he plays.

Morneau would represent the most ideal situation for New York: A former AL MVP, with a power left-handed bat that could take advantage of the short porch in right field, and an expiring contract.

If Teixeira is lost for the entire season, Morneau wouldn't clog up payroll or a roster spot in 2014 and beyond.

Headley can either be considered a one-year wonder or a star that emerged last season. Considering that he's only arbitration eligible after this season, the Yankees would likely jump at the chance to acquire him from San Diego.

Utley as a corner infielder may seem way outside-the-box, but don't rule anything out for the 2013 Yankees.

Chase Utley is wasting no time in 2013. He already clocked his 200th HR and now sits a double shy of his 1st career cycle. #OpeningDay

To be clear, he has played some first base in his career, including limited games during each of his first five seasons.

While the Phillies are attempting to bounce back from a poor 2012, the odds in the NL East are stacked against them. Much like the thinking with Utley's teammate, Roy Halladay, Philadelphia could look to move the impending free agent this summer.

As for Utley, when healthy, he can hit like a corner infielder. Robinson Cano is clearly entrenched at second base, but Utley's bat can play at 1B or DH for New York. Furthermore, the versatility would only help Utley as he ventures out in to free agency for the first time in his career.